Tissue-engineered Bicipital Autologous Tendon Patch Enhances Massive Rotator Cuff Defect Repair in a Rabbit Infraspinatus Tendon Defect Model.

Background: Massive rotator cuff defects represent an important source of shoulder pain and functional debilitation, substantially diminishing patients' quality of life. The primary treatment of massive rotator cuff defects includes complete or partial repair and patch augmentation. However, because of the tendon's limited regenerative ability, the tendon retear risk after rotator cuff defect repair is still high.

Gel microspheres enhance the stemness of ADSCs by regulating cell-ECM interaction.

The gel microsphere culture system (GMCS) showed various advantages for mesenchymal stem cell (MSC) expansion and delivery, such as high specific surface area, small and regular shape, extensive adjustability, and biomimetic properties. Although various technologies and materials have been developed to promote the development of gel microspheres, the differences in the biological status of MSCs between the GMCS and the traditional Petri dish culture system (PDCS) are still unknown, hindering gel microspheres from becoming a culture system as widely used as petri dishes. In the previous study, an excellent "all-in-one" GMCS has been established for the expansion of human adipose-derived MSCs (hADSCs), which showed convenient cell culture operation.

Grey Correlation Analysis of the Durability of Steel Fiber-Reinforced Concrete under Environmental Action.

The interface performance of steel fiber-reinforced concrete (SFRC) is a critical factor in determining mechanical properties and durability. The degradation of the concrete matrix and micro-structure interface is caused by environmental erosion, which shortens the service life of the structure design. Considering different volume contents of steel fiber (0%, 1%, 2%), the failure mechanism of SFRC under different environmental erosion conditions was studied through a laboratory test scheme.

Mesenchymal Stem Cells-Hydrogel Microspheres System for Bone Regeneration in Calvarial Defects.

The repair of large bone defects in clinic is a challenge and urgently needs to be solved. Tissue engineering is a promising therapeutic strategy for bone defect repair. In this study, hydrogel microspheres (HMs) were fabricated to act as carriers for bone marrow mesenchymal stem cells (BMSCs) to adhere and proliferate.

"Musical dish" efficiently induces osteogenic differentiation of mesenchymal stem cells through music derived microstretch with variable frequency.

Nonuniform microstretching (NUMS) naturally occurs in real bone tissues in vivo, but its profound effects have not been identified yet. In order to explore the biological effects of NUMS and static stretch (uniform stretch [US]) on cells, a new "musical dish" device was developed. Musical signal was used to provide NUMS to cells.

Seamless and early gap healing of osteochondral defects by autologous mosaicplasty combined with bioactive supramolecular nanofiber-enabled gelatin methacryloyl (BSN-GelMA) hydrogel.

Autologous mosaicplasty is a common approach used to treat osteochondral defects in clinical practice. Gap integration between host and transplanted plugs requires bone tissue reservation and hyaline cartilage regeneration without uneven surface, graft necrosis and sclerosis. However, poor gap integration is a serious concern, which eventually leads to deterioration of joint function.

Identification of an Ultrathin Osteochondral Interface Tissue with Specific Nanostructure at the Human Knee Joint.

Cartilage adheres to subchondral bone via a specific osteochondral interface tissue where forces are transferred from soft cartilage to hard bone without conferring fatigue damage over a lifetime of load cycles. However, the fine structure and mechanical properties of the osteochondral interface tissue remain unclear. Here, we identified an ultrathin ∼20-30 μm graded calcified region with two-layered micronano structures of osteochondral interface tissue in the human knee joint, which exhibited characteristic biomolecular compositions and complex nanocrystals assembly.

In-cytoplasm mitochondrial transplantation for mesenchymal stem cells engineering and tissue regeneration.

Stem cell therapies are unsatisfactory due to poor cell survival and engraftment. Stem cell used for therapy must be properly "tuned" for a harsh in vivo environment. Herein, we report that transfer of exogenous mitochondria (mito) to adipose-derived mesenchymal stem cells (ADSCs) can effectively boost their energy levels, enabling efficient cell engraftment.

Advanced hydrogels for the repair of cartilage defects and regeneration.

Cartilage defects are one of the most common symptoms of osteoarthritis (OA), a degenerative disease that affects millions of people world-wide and places a significant socio-economic burden on society. Hydrogels, which are a class of biomaterials that are elastic, and display smooth surfaces while exhibiting high water content, are promising candidates for cartilage regeneration. In recent years, various kinds of hydrogels have been developed and applied for the repair of cartilage defects or , some of which are hopeful to enter clinical trials.

Tissue-Adhesive Paint of Silk Microparticles for Articular Surface Cartilage Regeneration.

Current biomaterials and tissue engineering techniques have shown a promising efficacy on full-thickness articular cartilage defect repair in clinical practice. However, due to the difficulty of implanting biomaterials or tissue engineering constructs into a partial-thickness cartilage defect, it remains a challenge to provide a satisfactory cure in joint surface regeneration in the early and middle stages of osteoarthritis. In this study, we focused on a ready-to-use tissue-adhesive joint surface paint (JS-Paint) capable of promoting and enhancing articular surface cartilage regeneration.

"All-in-One" Gel System for Whole Procedure of Stem-Cell Amplification and Tissue Engineering.

Microsphere (MS)-based systems provides great advantages for cell expansion and transplantation due to their high surface-to-volume ratio and biomimetic environment. However, a MS-based system that includes cell attachment, proliferation, passage, harvest, cryopreservation, and tissue engineering together has not been realized yet. An "all-in-one" gel MS-based system is established for human adipose-derived mesenchymal stem cells (hADSCs), realizing real 3D culture with enhanced expansion efficiency and simplified serial cell culture operations, and construction of macrotissues with uniform cell distribution and specific function.

Single-Cell Profiles and Clinically Useful Properties of Human Mesenchymal Stem Cells of Adipose and Bone Marrow Origin.

Background: Mesenchymal stem cells (MSCs) can be isolated from various tissues and can present themselves as a promising cell source for cell-based therapies. Although adipose- and bone marrow-derived mesenchymal stem cells have already been used in a considerable number of clinical trials for osteoarthritis treatment, systematic analyses from single- to bulk-cell resolution as well as clinical outcomes of these 2 MSCs are still insufficient.

Purpose: To explore the characteristics and differences of adipose-derived stem cells (ADSCs) and bone marrow MSCs (BMSCs) at single- and bulk-cell levels, to study the clinical outcomes of these 2 cells on the treatment of osteoarthritis, and to provide potential guidance on the more precise clinical application of these MSCs.

Genome-Wide Determination of Gene Essentiality by Transposon Insertion Sequencing in Yeast Pichia pastoris.

In many prokaryotes but limited eukaryotic species, the combination of transposon mutagenesis and high-throughput sequencing has greatly accelerated the identification of essential genes. Here we successfully applied this technique to the methylotrophic yeast Pichia pastoris and classified its conditionally essential/non-essential gene sets. Firstly, we showed that two DNA transposons, TcBuster and Sleeping beauty, had high transposition activities in P.